Reinforced semi flexible pavement

ABSTRACT

Pavement structure  
     for use in applications where special requirements to load bearing capacity and durability must be fulfilled, for example in warehouses, on docks, airports, distribution centres, retail areas, goods terminals, industrial floors, production halls and other places where heavy loads and excessive wear can be expected, said material consists of an asphalt part and a slurry part, said asphalt having a porosity of 20-40%, and said slurry substantially completely fills the voids in the asphalt, the slurry being a composite material comprising a binder, additives and water, and optionally cement, microsilica, flyash or other pozzolanic materials as well as optionally sand or other fine aggregates, wherein the pavement material ( 1 ) comprises at least one reinforcement layer ( 3, 4, 21 ). Furthermore, a method for the construction of a pavement, as well as use of a material is disclosed.

FIELD OF THE INVENTION

[0001] The present invention relates to a pavement structure comprisinga porous asphalt part and a composite material part, said compositematerial part comprising a binder, wherein said composite materialsubstantially completely fills the voids in the asphalt.

BACKGROUND OF THE INVENTION

[0002] Pavement structures of this type are used in applications wherespecial requirements to load bearing capacity and durability must befulfilled, for example in warehouses, on docks, airports, distributioncentres, retail areas, goods terminals, industrial floors, productionhalls, shopping centres, roads and other places where heavy loads andexcessive durability is needed.

[0003] Pavements of this type provides some important advantages ascompared to ordinary pavements. When pavements or roads traditionallyare constructed in the applications mentioned above, eitherconstructions consisting of only concrete or only asphalt are applied.

[0004] Concrete pavements can give a very strong construction whichgives a high load bearing capacity, and high durability. On the otherhand the concrete pavement is compelled to have flexible joints, as allother concrete constructions, for the construction to be able to move,due to changes in temperature, humidity which again causes shrinkage incement based materials. Often it is not desirable to have joints in apavement, as these joints constitute an area where the concrete can bedamaged due to high loads on the edge, which can cause the concrete tocrack and break. Furthermore, joints must be maintained which results inextra maintenance costs for the user, resulting in time where thepavement cannot be used.

[0005] Asphalt pavements are very flexible and do not need joints. Theload bearing capacity of a traditional asphalt layer is relatively low,which makes it unsuitable for use in the applications mentioned abovewhen the sub-base is not sufficiently rigid.

[0006] The combination of asphalt and concrete material enjoys the goodcharacteristics of both materials, if they are correctly combined. Bycombining the two materials the pavement has a relatively high loadbearing capacity, good flexibility, high durability and does not needjoints. Furthermore is the material substantially frost-resistant andvery resistant to harmful chemicals and pollutants.

[0007] Materials of this type has long been used in the industry withgood results. Examples of such materials are sold under the registerednames Salviacim, Betophalt by Alfred Kunz AG, Microfond by DyckerhoffBaustoffsysteme or Densiphalt® by Densit A/S. These materials are allcombinations of asphalt and concrete or concrete-like materials, wherethe asphalt is placed first with a porosity of 20%-40%. Thereafter theconcrete is placed in the shape of a slurry which will, to a certainextent, fill out the voids in the asphalt matrix and subsequentlyharden. The combined material thereafter has a very low porosity and a,in comparison to regular asphalt, high compressive strength, whichtogether gives the material the special characteristics mentioned above.

[0008] Pavements of this type furthermore has very good resistance tofrost and pollutants in the environment in which they are placed, due totheir very compact structure and low permeabillity.

[0009] The abovementioned pavements all have very good durabilitycharacteristics and usually have a longer service life than eitherconcrete or asphalt. If however the sub-base settles or subsides thepavement will lose part of its support and consequently will crack. Thenormal procedure in order to restore the pavement is to cut out thecracked section, renovate the sub-base and place a new layer of forexample Densiphalt®. The replacement/renovation often takes place longafter the initial cracking occurred, as these pavements are oftensubjected to heavy and/or intense use, and airports, ports, ports, etc.seldom have time where the area is not needed and this type ofmaintenance can be carried out. The user therefore has an extended timewherein the pavement is not performing as it is designed to do.Especially in airports can this cause severe problems. These kinds ofpavements are often placed where there is the heaviest traffic, forexample in the so called channelised traffic paths, leading theaircrafts from and to the aprons for loading and unloading passengers,cargo and/or fuel.

BRIEF DISCLOSURE OF THE INVENTION

[0010] The present invention therefore addresses the problem of how toturn a wearing course with high durability characteristics, i.e. thepavement into a load bearing course.

[0011] The above mentioned problem is present in the situationsdescribed above and can also be seen as a means to extend the servicelife and minimize the downtime of pavement structures, where thepavement becomes unusable due to cracking caused by settlement of thebase.

[0012] This problem is solved by the present invention, by placingreinforcement in the pavement layer.

[0013] Historically it has not been thought feasible to reinforceasphalt layers. Due to the viscosity of the bitumen it has not beenpossible to reinforce asphalt with traditional steel reinforcements, butonly with certain textile reinforcements such as geotextiles. Theasphalt structure is not strong enough to transmit forces to thereinforcement. Asphalt consists of a mixture of gravel and bitumen,wherein the bitumen acts as a flexible binder, keeping the asphaltmatrix together. When the reinforced asphalt structure is subjected tobending forces the bending moment is transmitted to the reinforcement asshear forces in the zone around the reinforcement and then from thematrix around the reinforcement into tension in the reinforcementwhereby the tension characteristics are utilised. Due to the soft andflexible nature of bitumen, the bitumen slips its grip around thereinforcement, and cannot hold the reinforcement, whereby no shearforces can be transmitted to the reinforcement. Consequently, thereinforcement has only a very limited effect on the asphalt layer.

[0014] Reinforcing concrete constructions with steel reinforcement iswell known in the art, and will not be further discussed here. Referenceis made to the many textbooks on the subject.

[0015] The pavements consisting of mainly asphalt with a void filling ofa slurry comprising a binder, has not previously been reinforced. Thisis probably due to the known problems with reinforcing asphalt asdescribed above.

DETAILED DESCRIPTION OF THE INVENTION

[0016] In this application slurry is used to characterise a materialcomprising a binder, and different additives. The binder can be chosenamong different cement materials as mentioned below as well as amongother hydraulic binders, for example gypsum or lime, or polymer basedbinders, for example different suitable epoxy products or cement basedpolymer-modified binders. The slurry can in further embodiments alsocontain microsilica, flyash or other pozzolanic fillers as well as sand,other fine aggregates or polymer-based fillers.

[0017] The slurry can be produced from a cement or other hydraulicbinder. The binder particles will preferably be fine particles having asize in the range of from about 0.5 micro-metre to about 100micro-metres. In a particularly preferred embodiment, the fine particlessuch as cement particles are combined with ultrafine particles having asize in the range of from about 5 nano-metres to about 0.5 micro-metre.Typically, the average particle size of the ultrafine particles will beat least one order of magnitude smaller than the average size of thefine particles, thereby allowing the ultrafine particles to becomesubstantially uniformly distributed in the voids between densely packedfine particles to result in an extremely hard and dense matrix thatprovides optimal resistance against ingress of aggressive and harmfulchemicals. In these embodiments, the fine particles will typicallycomprise at least one cement selected from the group consisting ofPortland cement, low-alkali cement, sulphate-resistant cement,refractory cement, aluminate cement, slag cement and pozzolanic cement,and the ultrafine particles will typically comprise particles selectedfrom the group consisting of silica fume and oxides such as iron oxideand titanium dioxide.

[0018] A slurry based on cement and silica fume is especially preferred.In this case, and when using a combination of fine particles andultrafine particles in general as discussed above, the slurry willtypically be prepared from a mixture comprising ultrafine particles inan amount of about 5-50% by volume based on the total volume of the fineparticles and ultrafine particles in the mixture. More typically, theamount of ultrafine particles will be about 10-40% by volume, such asabout 15-30% by volume, based on the total volume of the fine particlesand ultrafine particles.

[0019] In such mixtures, the amount of water is preferably kept to theminimum required in order to wet the particles and provide a mixturewith the required workability. Water is therefore normally added to themixture in a volume ratio between water and fine+ultrafine particles ofabout 0.25-1.5, typically about 0.41.2, such as about 0.55-1.0.

[0020] When using a rather small amount of water as indicated above in acement-based mixture, the mixture will typically be prepared using asuitable effective amount of a surface-active dispersing agent (alsoknown as a water-reducing agent or plasticizer), preferably a dispersingagent of the type known in the art as “concrete superplasticizers”.Examples of suitable concrete superplasticizers are naphthalene-based,melamine-based, vinyl-based, acrylic-based and carboxylic acid-basedproducts, as well as mixtures thereof and derivatives such as vinylcopolymers.

[0021] The concrete superplasticizer or other dispersing agent istypically incorporated into the mixture (either the dry mixture beforewater has been added or a wet mixture to which some or all of the waterhas already been added) in an amount of about 0.01-5% (dry weight basedon the total weight of the fine and ultrafine particles), typicallyabout 0.05-4%, more typically about 0.1-3%, such as about 0.2-2%. Itwill be understood that the amount of superplasticizer to be used ineach individual case will depend in part on the nature of thesuperplasticizer. For example, when using one of the new generation ofhighly effective vinyl-, acrylic- or carboxylic acid-basedsuperplasticizers, the required dispersing effect can be obtained with asignificantly smaller amount of superplasticizer than when using e.g. anaphthalene sulphonic acid/formaldehyde or melamine sulphonicacid/formaldehyde condensation product Thus, the concretesuperplasticizer should be used in an “effective” amount, i.e. effectivefor the given superplasticizer and in the given particle system toobtain the desired dispersing effect in the mixture using only theintended amount of water. The slurry must initially be very fluid inorder to be able to penetrate and fill the voids in the asphalt matrix.In order for other materials in the art to attain a sufficient voidfiling in the asphalt matrix, it has been necessary to vibrate theslurry into the asphalt matrix. With the present invention using amaterial as described above this is not necessary, as this slurrysubstantially fills all voids without vibrating, due to the materialsexcellent flowability. When not having to vibrate the pavement at leasttwo advantages are obtained. Firstly, when vibrating a relatively freshporous asphalt it is easy to destroy the initial pore/void structure,and thereby difficult to control the porosity. The porosity is veryimportant for the final structure as the porosity determines how muchslurry can be accommodated in the matrix. Secondly, by not having tovibrate, a work operation is saved which limits the time when thepavement cannot be used and furthermore makes the procedure ofinstalling the pavement more economic.

[0022] An example of a slurry material as described above, is the slurrypart of the material sold under the name Densiphalt®. This material hasshown a better ability to penetrate and fill the voids in an asphaltstructure, than other materials of this type. It is this fact togetherwith the strength characteristics of the composite material, which makesit possible to effectively utilise the tension characteristics of areinforcement arranged in the matrix.

[0023] The slurry will harden and thereby attain at least two, for theapplication disclosed in this patent, very important characteristics,namely compressive strength, and a dense and compact micro-structure.

[0024] Within the scope of this invention the hardend slurry is calledcomposite material.

[0025] The compressive strength of the composite material depends onmany factors, for example the mix composition of the composite material,water and air content. From an economic viewpoint it is interesting todesign the composite material for a particular use. The compressivestrength can be varied by changing the mix composition, as describedabove. The compressive strength of the composite material, as forexample in Densiphalt® is preferably around 110 MPa, for example in therange 100 MPa to 120 MPa, for other applications it might be lower, forexample in the range 85 MPa to 120 MPa or 75 Mpa to 100 MPa or stilllower 65 MPa to 90 MPa, or lower. Also for other applications thecompressive strength may be in a higher range for example 110 MPa to 130MPa or 120 MPa to 145 MPa or still higher, for example 135 MPa to 145MPa or still higher, for example 135 MPa to 160 MPa or above.

[0026] The present invention has proven that it is possible tostrengthen these materials with a reinforcement, and utilise the tensioncharacteristics of a reinforcement. By using a slurry with extremecharacteristics as the slurry used in Densiphalte®, tests have shownthat the pavement becomes more resistant to bending. Test resultsindicate that the pavement structure can be calculated in a fashionsimilar to conventional reinforced concrete.

[0027] The structure consequently has attained all the good durabilitycharacteristics of the original materials. Densiphalt® has an extremlygood ability to transmit the above-mentioned shear forces into tensionin the reinforcement. This is due to the very dense and finemicro-structure of the composite material. The pavement structure hasobtained strength characteristics almost comparable to conventionalreinforced concrete. Hereby is achieved that the pavement has a muchimproved load distributing ability, whereby the pavement will be lesssensitive to settlement in the base layers, as well as cracking due tothis settling. Furthermore because the composite material is able totransmit forces to the reinforcement, the pavement structure as a wholewill crack in a pattern similar to reinforced concrete. When reinforcedconcrete is loaded and cracks, this happens as very fine cracks evenlydistributed along the side of the object in tension.

[0028] The type of pavements, of which the present invention is animprovement, are traditionally made in layers having a thickness ofbetween 40 and 60 mm. When layers of this thickness are reinforcedaccording to the invention, the layer as a whole only gains a limitedresistance against bending. The load distributing and crack distributingcharacteristics however improves significantly, so that a pavementaccording to the invention, gains some very advantageous characteristicsin comparison to un-reinforced pavements known in the art. As the layerthickness increases, for example up to 100 mm or more preferably up to150 mm or still more preferably up to 200 mm or thicker, the bendingresistance also increases as well as the other advantageouscharacteristics, such as crack and load distribution.

[0029] Therefore by varying the layer thickness and compressive strengthof the composite material, a pavement can be designed specifically to aspecific use. The different parameters, i.e. composition of compositematerial, type of reinforcement and layer thickness, as well as porosityof the asphalt, can be chosen within the ranges of the patent, in orderto design a pavement for different applications.

[0030] In some applications of the pavement structure or materialaccording to the invention, special requirements to the appearance andsurface characteristics of the layer must be fulfilled. This isespecially important in shopping centres, airports and other areas whereheavy and/or intense pedestrian use can be expected. It is also withinthe scope of the invention to use technical bitumen in the asphaltmatrix. Technical bitumen is a polymer-based material with similarcharacteristics to bitumen. The material is colourless, but can be dyedto any colour. The same is true about some of the epoxy-based binderswhich can be used as binder material in the slurry material. Byutilising these characteristics the pavement can be given an appearanceaccording to the architect's requirements, and still maintain thecharacteristics of the pavement structure. Furthermore is bitumenslightly sticky, which is not desirable in pedestrian areas. Thisstickiness is avoided by using technical bitumen.

[0031] The pavement according to the invention consequently achievessome important advantages in comparison to known materials: 1) due tothe improved load bearing capability, the pavement will be able tohandle heavier loads as the load will be better distributed through thepavement layer and 2) with excessive loading the underside, i.e. theside of the pavement opposite the surface where the load is placed, willcrack in the shape of many small cracks evenly distributed along thetension zone of the underside of the structure, and 3) because of theductility of the material helped by the reinforcement the fatiguestrength of the pavement is vastly improved, which again results in amuch improved service life, and consequently less maintenance and downtime for the pavement.

[0032] When constructing a pavement according to the invention thesub-base is prepared as known in the art. Thereafter a first asphaltlayer is placed on the sub-base. On the first asphalt layer a firstreinforcement layer is arranged, and then another asphalt layer isplaced. In constructions where only one reinforcement layer is neededthe second asphalt layer will be the final layer. Where two or morelayers of reinforcement are needed, another asphalt layer will beplaced, and another reinforcement layer and so on alternating the layersuntil the desired number of reinforcement layers are arranged in theasphalt matrix, and the uppermost finishing asphalt layer can be placed.The asphalt matrix is placed with a porosity of between 20% and 40%,more preferably 22-35% and still more preferably between 25% and 30%.After the asphalt matrix has cooled, the voids in the asphalt matrix issubstantially completely filled with the slurry (composite material). Ina further process step the finished surface can be given a treatment,for example a curing membrane, in order to avoid excessive drying of thepavement during hardening of the composite material. Also the pavementcan be given a treatment to roughen the surface, in order to improveskid resistance. This treatment can be carried out by for example asteel ball shot blasting process, during which the uppermost thin skinof composite material is removed, in order to expose a rougher structureof composite material and gravel.

[0033] The invention also comprises the use of a reinforcement in amatrix comprising a composite material part and an asphalt materialpart, said composite material part comprises a binder and differentadditives, said composite material having a compressive strength in therange from below 60 MPa to more than 160 MPa, preferably from 75 MPa to145 MPa, still more preferably from 85 MPa to 130 MPa, yet still morepreferably from 100 MPa to 120 MPa, but even more preferably around 110MPa, said composite material substantially completely filling voids inan asphalt-matrix with a porosity between 20% and 40%, more preferablybetween 22% and 35% and still more preferably between 25% and 30%.

[0034] In further advantageous embodiments the reinforcement can besteel rods or wires, carbon wires, stainless steel rods or wires,modified polymers, glassfibres or glassfibre spun wires or strands. Thereinforcement can be used as rods, strands, wires, nets, mats or mesh.Also in this application three dimensional reinforcement structures canbe used. For example when the reinforcement is arranged in anintermediate asphalt layer. This is especially useful when thereinforcement is in the shape of fibres.

DESCRIPTION OF THE DRAWINGS

[0035] In the following detailed description of advantageous embodimentsof the invention reference will be made to the accompanying figures,wherein

[0036]FIGS. 1a, 2 a shows a known pavement in a uncracked and crackedstate;

[0037]FIGS. 1b, 2 b shows a pavement according to the inventionuncracked and cracked;

[0038]FIG. 3 illustrates test specimens;

[0039]FIG. 4 illustrates laboratory test rig;

[0040]FIGS. 5a and 5 b illustrate the relationship between load anddeflection;

[0041]FIG. 6 is a table showing the asphalt recipe;

[0042]FIG. 7 is a table showing the mix proportions for Densiphalt®mortar;

[0043]FIG. 8 shows crack patterns on test specimens; and

[0044]FIG. 9 is a modelled cross section of pavement.

[0045] In FIG. 1a is schematically shown a traditional pavement 1 of thetype comprising an asphalt matrix with a porosity in the range 20-40%,and a composite material (15) completely filling out the voids in theasphalt matrix (16). A schematic cross section of the material is shownin FIG. 9. The pavement is placed on a sub-base 2, which is generallyknown in the art. Hereby is created a pavement 1 combining theflexibility of asphalt with the durability and strength characteristicsof concrete, resulting in a joint-free pavement.

[0046] In FIG. 1b is schematically illustrated an inventive pavement 1according to the invention, with in this example two reinforcementlayers 3,4, one layer 4 placed in the lower part and one layer 3 placedin the upper part of the pavement layer 1. In FIG. 2a is illustrated howthe pavement without reinforcement will crack with few large cracks 5,because of a subsiding base 2 creating voids 7 between the pavement 1and the sub-base 2, and high loads on the surface of the pavement 1.

[0047] In FIG. 2b is illustrated the comparable situation, but with apavement according to the invention. As will be seen from the laboratoryresults, outlined below, the bearing capacity of the pavement accordingto the invention is more than three times that of the unreinforced knownpavements of this type. The crack patterns will therefore only developdue to higher loads. Because of the composite materials intimate contactwith the reinforcement, crack patterns comparable to conventionalconcrete will show.

[0048] In conventional concrete exposed to bending, fine evenlydistributed cracks will appear in the concrete on the side subjected totension. Concrete can only take a small fraction of its compressivestrength as tension, for example a concrete with a characteristiccompressive strength of 35 MPa can be subjected to about 1,9 N/mm² intension without cracking. When cracking in the concrete occurs, thetension forces will be transmitted to the reinforcement. Steel'sreinforcement can take very high tensile stresses before failure, andtherefore a reinforced concrete construction utilises the concretecharacteristics in compression and the steels characteristics intension. This co-action is based on the assumption that the concrete isable to grip or hold the steel reinforcement sufficiently to transmitthe forces to the steel reinforcement.

[0049] The situation illustrated in FIG. 2b is as described above causedby a significantly higher load and the creation of voids 7 between thepavement 1 and the sub-base 2. The fine cracks 6 will be evenlydistributed along the side of the pavement exposed to tension stresses.

[0050] In laboratory experiments tests have shown that a reinforcedDensiphalt® pavement achieved impressive characteristics in comparisonto a non-reinforced pavement of this type. The tests were carried out onspecimens 100 as illustrated in FIG. 3. All specimens had the same outerdimensions, but varied in the placement and type of reinforcement 21.All reinforcements 21 however were welded mesh structures. Each specimenwas made from a type 20 open grade asphalt (OGA) produced in a standardasphalt plant and stored in containers. Before being placed in thespecimen moulds, the asphalt was re-heated to 150° C. Details of theasphalt mix are listed in the table illustrated in FIG. 6. The bottomlayer of the asphalt was then placed in the mould and manuallycompacted. Thereafter a reinforcement mesh was placed and the mould wasfilled with asphalt, and manually compacted. Where there are placed tworeinforcement layers in the specimen, a second portion of asphalt wasplaced on top of the first reinforcement layer, which second layer wasmanually compacted, and the second reinforcement layer was then arrangedon this layer, whereafter the top layer of asphalt was placed andmanually compacted.

[0051] After the asphalt had cooled the asphalt matrix was filled withDensiphalte® mortar mixed as shown in the table in FIG. 7. The specimenswere then cured for 1 week at 20° C.

[0052] The specimens 100 were placed in a test rig 20 as illustrated inFIG. 4, and two equal loads 22 were applied equidistant from the centreof the specimen 100. A displacement transducer 23 was arrangedunderneath and in contact with the specimen 100. As the loads 22 areincreased, the specimen will bend and depress the transducer 23. Therelationship between load and deflection, as measured by the transduceris illustrated in FIGS. 5a and 5 b.

[0053] All specimens were loaded to failure, and their crack patternswere recorded, see FIG. 8. Cracks 25 are illustrated as lines notrepresenting the actual crack width. From FIG. 8 is it clear to see thatan unreinforced specimen (specimen 1) has failure at a low load level,and furthermore failure occurs due to the creation of one large crack.The other specimens (specimen 2-7) all exhibits the formation of a crackpattern, comparable to crack patterns known from conventional reinforcedconcrete. Furthermore, these specimens could all be loaded to muchhigher ultimate loads (see FIG. 5b) and endure larger deflections beforefailure.

[0054] From the above mentioned laboratory tests is it evident that thereinforced Densiphalt® pavement system has improved characteristics ascompared to similar systems without reinforcement Furthermore the testsshow that with the slurry/composite material filling out the voids inthe asphalt matrix is it possible to utilise the tension characteristicsof a cast in reinforcement.

[0055] In the test series mentioned above traditional welded steel meshreinforcement was used, but also steel or carbon wires, modifiedpolymers, glassfibres or glassfibre spun wires and similar types ofmaterials can be used as reinforcement.

[0056] In the pavement-system sold as Densiphalt® the slurry/compositematerial has an average compressive strength of around 110 MPa, but alsoslurries with lesser or higher strengths can be used. This system is notdependent on the compressive strength of the composite material alone,but on attaining a fine micro-structure which will have an intimatecontact with the reinforcement, as well as having a strongskeleton-structure in the asphalt matrix. The material further has anexceptional ability to fill all the voids in the asphalt-skeleton. Theseaspects together makes it possible to transmit the forces arising fromloads on the surface of the pavement. These forces occur as shear in thepavement layer and moments due to bending in the pavement structure. Themoments, as described above, must be transformed into tension stressesin the reinforcement in order to achieve the load distribution,resulting in a multitude of fine cracks, as illustrated in FIG. 8. Evenif the unreinforced pavement could absorb the shear forces, the tensionin the underside from the bending moment would cause one large crack, asillustrated in FIG. 8, specimen 1, whereby the pavement would bedestroyed. With the present invention, the cracks 25 are distributedalong the underside exposed to tension indicating very good loaddistributing as well as a strong connection between theasphalt-composite mix and the embedded reinforcement, whereby the wholepavement structure becomes much stronger. The laboratory results show upto more than 3 times ultimate loads with larger deflections, see FIG.5b.

1. Pavement structure comprising a porous asphalt part and a composite material part, said composite material part comprising a binder, wherein said composite material substantially completely fills voids in the asphalt part characterised in that the pavement structure comprises at least one reinforcement layer (3,4,21).
 2. Pavement structure according to claim 1, characterised in that the reinforcement (3,4,21) is steel rods or wires, carbon wires, stainless steel rods or wires, modified and/or reinforced polymers, glassfibres or glassfibre spun wires.
 3. Pavement structure according to claim 1, characterised in that the reinforcement is a net or mesh.
 4. Pavement structure according to claim 1, characterised in that the composite material has a compressive strength in the range from below 60 MPa to more than 160 MPa, preferably from 75 MPa to 145 MPa, still more preferably from 85 MPa to 130 MPa, yet still more preferably from 100 MPa to 120 MPa, and still more preferably around 10 MPa.
 5. Pavement structure according to claim 1, characterised in that two reinforcement layers (3,4) are arranged in the pavement (1), one layer (4) in the lower part of the matrix and one layer (3) in the upper part of the matrix.
 6. Pavement structure according to claim 1, characterised in that the asphalt-matrix has a porosity in the range 20% to 40%, more preferably 22-35% and still more preferably between 25-30%, by volume.
 7. Pavement structure according to claim 1, characterised in that the composite material additionally and optionally may contain materials chosen among the following material groups: flyash, polymer modified cement-based binders, pozzolanic fillers, microsilica, sand, or other fine aggregate.
 8. Pavement structure according to claim 1, characterised in that the bitumen in the asphalt-matrix may be bitumen or technical bitumen.
 9. Pavement structure according to claim 1, characterised in that the binder is chosen among cements selected from the group consisting of Portland cement, low-alkali cement, sulphate-resistant cement, refractory cement, aluminate cement, slag cement and pozzolanic cement or epoxy-based polymer materials with binder qualities or hydraulic binders such as gypsum or lime.
 10. Use of a reinforcement in a matrix comprising a porous asphalt part and a composite material part, said material part comprises a binder and substantially completely fills voids in the asphalt part.
 11. Use of a reinforcement in a matrix according to claim 10, wherein the composite material part comprises a binder and different additives, said composite material having a compressive strength in the range from below 60 MPa to more than 160 MPa, preferably from 75 MPa to 145 MPa, still more preferably from 85 MPa to 130 MPa, yet still more preferably from 100 MPa to 120 MPa, but even more preferably around 110 MPa, said composite material substantially completely filling voids in an asphalt-matrix with a porosity between 20% and 40%, more preferably between 22% and 35% and still more preferably between 25% and 30%.
 12. Method for making a pavement structure comprising a porous asphalt part and a composite material part, said composite material part comprising a binder, wherein said composite material substantially completely fills voids in the asphalt part and further that the pavement structure comprises at least one reinforcement layer, the method comprising the following steps: a sub-base is prepared and compacted; a first asphalt layer is placed on the sub-base; a first reinforcement is arranged on the first asphalt layer; a second asphalt layer is arranged on the reinforcement; the asphalt layers forming an asphalt matrix which has a porosity in the range 20% to 40%; the voids in the asphalt matrix are substantially completely filled with a slurry, said slurry comprises a binder, and the slurry is allowed to harden to form the composite material part.
 13. A method according to claim 12, wherein a second reinforcement layer can be arranged on top of the second asphalt layer, and the second reinforcement layer is covered with a third asphalt layer, before the slurry is filled in the voids in the matrix.
 14. A method according to claim 12, wherein the steps of arranging another reinforcement on the previous asphalt layer is repeated, until the desired number of reinforcement layers is reached whereafter the final asphalt layer is placed, before filling the asphalt matrix with the slurry. 